RT Journal Article SR Electronic T1 Cyberspace Chat: When finasteride suddenly stops working—is it counterfeit? JF International Society of Hair Restoration Surgery FD Publication of the International Society of Hair Restoration Surgery SP 221 OP 222 DO 10.33589/23.6.0221 VO 23 IS 6 A1 Sharon A. Keene YR 2013 UL http://www.ISHRS-HTForum.org/content/23/6/221.abstract